Generate faces form single mesh edge?
There are three distinct ways to do this.


Either use Bezier Curve objects. They have the advantage of being simple to edit for tubular structures, can easily bend and make curves, and can have custom sections





Use a mesh with a Wireframe modifier. It is fast to process and is a mesh, so can have a lot more modifiers on top than a bezier curve





Use a skin modifier. It is slower to process and computationally heavy to handle, but will generate cleaner topology and have proper intersections at the joints.